Bracket base



FIG. 1 is a perspective view of a bracket base showing our new design;

FIG. 2 is a side view thereof;

FIG. 3 is an opposite side view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a bottom view thereof;

FIG. 6 is an end view thereof, the opposite end view being substantially identical; and,

FIG. 7 is a section view thereof, taken along the section line 7-7 indicated in FIG. 2. 

CLAIM The ornamental design for a bracket base, as shown and described. 